基于电力电子辅助式有载分接开关的Sen变压器开关暂态建模与分析

提出了基于电力电子辅助式有载分接开关（OLTC）的Sen变压器（ST）的开关暂态模型，并对切换过程进行了分析，包括基本的开关逻辑、重叠角和分接头短路的影响以及不同功率因数下最佳切换角的选择方法。基于T形等效电路和拉普拉斯变换建立了基于电力电子辅助式OLTC的ST的开关暂态模型。根据电力电子辅助式OLTC的拓扑结构，建立了基本的开关逻辑。分析了重叠角和分接头短路对切换过程的影响。通过对不同功率因数下切换过程的分析给出了最佳切换角的选择方法。借助MATLAB和PSCAD/EMTDC分别进行解析计算和时域仿真，验证了所提开关暂态模型、开关逻辑和最佳切换角选择方法的有效性，并表明可以在一个周期内完成切换。此外，通过切换角可以控制重叠角和短路电流峰值的大小。

Switching transient modeling and analysis of power-electronic-assisted on-load tap-changer based Sen transformer

The switching transient model of the power-electronic-assisted on-load tap-changer(OLTC) based Sen transformer(ST) is presented, and the switching process is analyzed, including the fundamental switching logic, the influence of overlap angle and short circuit of the tap-changer, and the selection method of optimum switching angle(OSA) under different power factors. The switching transient model of power-electronic-assisted OLTC based ST is developed based on T-equivalent circuit and Laplace transformation. The fundamental switching logic is established according to the topology of a power-electronic-assisted OLTC. The influence of overlap angle and short circuit of the tap-changer on the switching process is analyzed. The selection method of OSA is illustrated by analyzing the switching process at different power factors. With the help of MATLAB and PSCAD/EMTDC, analytical calculations and time-domain simulations are carried out to verify the effectiveness of the proposed switching transient model, the switching logic and the selection method of OSA, and show that a complete switching process is possible in less than one cycle. In addition, the magnitude of the overlap angle and the peak of the short circuit current can be controlled by the switching angle.